Armored cable connector

ABSTRACT

A cable connector terminates an armored cable in a knockout in a wall of an electrical enclosure. The connector includes a one-piece connector body having a forward end and plurality of side walls extending from the forward end in cantilevered fashion to define a cavity for receipt of an end of the cable. The forward end of the connector body is insertable into the knockout and the cantilevered side walls are deflectable to permit such insertion. The side walls further accommodate insertion of a cable into the cavity for retentively supporting the cable to the enclosure. The side walls of the connector body include outwardly extending tabs for engaging wall of the enclosure about the knockout. Side walls further include inwardly extending fingers for engaging the cable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.60/577,737, filed Jun. 7, 2004.

FIELD OF THE INVENTION

The present invention relates generally to a connector for terminatingthe end of an electrical cable. More particularly, the present inventionrelates to a one-piece connector for connecting a flexible armored cableto a knockout of an electrical enclosure.

BACKGROUND OF THE INVENTION

An electrical wire is typically terminated in a junction box, panel boxor other electrical enclosure. The wire enters the enclosure through anopening referred to as a knockout in a wall of the enclosure. In orderto terminate the wires in the enclosure, an end of a conduit (cable)which encloses the wires is attached to the enclosure at the knockout.

Not only are cable connectors of this type manufactured to effectelectrical engagement between the conduit and the electrical enclosure,these connectors should also provide strain relief attachment of thecable to the enclosure. Thus, when a load placed on the cable, tendingto pull the cable out from the enclosure is applied, the connectorshould adequately resist such a load and maintain the cable inmechanical and electrical engagement with the enclosure.

The art has seen a wide variety of connectors and termination devicesused to attach the conduit to the knockout of the electrical enclosure.Certain of these connectors are specifically designed for attachingflexible metallic armored conduits. These connectors also serve toeffect electrical engagement between the conduit and the electricalenclosure. Examples of such conduit connectors are shown in, amongothers, U.S. Pat. Nos. 3,858,151; 4,012,578; 4,021,604; 4,619,332;4,990,721; 6,034,326; and 6,114,630.

While each of these devices serve adequately for their intendedpurposes, there is a need for a conduit connector which allows ease ofinsertion and attachment to the knockout of the electrical enclosure andwhich securely retains the conduit to the enclosure. Moreover, it isdesirable to employ a conduit connector which is simple and costeffective to manufacture and assembled. Additionally, it is desirable toprovide a conduit connector which permits the subsequent insertion ofthe conduit into the connector after the connector has been attached tothe enclosure.

SUMMARY OF THE INVENTION

The present invention provides a cable connector for terminating an endof a cable to a knockout of an enclosure. The connector includes aone-piece connector body having a forward end and plurality of sidewalls extending rearwardly from said forward end in cantilevered fashionto form a cavity for receipt of an end of the cable. The forward end ofthe connector body is insertable into the knockout with the cantileveredside walls being deflectable to permit retentive insertion thereinto.The side walls further accommodate insertion of the cable end into thecavity for retentively supporting the cable to the enclosure.

The side walls may further include outwardly extending tabs forengagement with the enclosure about the knockout. Additionally, the sidewalls may include inwardly extending fingers for engaging the cable,especially flexible armored cable.

The present invention also provides a method for terminating an end of acable to a knockout of an enclosure. A connector body having a forwardend including a plurality of side walls extending from the forward endin cantilevered fashion is provided. The connector body defines acavity. The forward end of the connector body is inserted into theknockout with the side walls deflecting to permit the insertion.Thereafter, the cable end is inserted into the cavity of the connectorbody in order to retentively support the cable to the enclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational showing, partially in section, of theconnector of the present invention terminating an armored cable to anelectrical enclosure.

FIGS. 2, 3 and 4 show front, side and perspective views, respectively,of the first stage of manufacture of the connector of the presentinvention.

FIGS. 5, 6 and 7 show front, side and perspective views, respectively,of the second stage of manufacture of the connector of the presentinvention.

FIGS. 8, 9, 10, 11, 12, and 13 show front, side sectional, rear side,front perspective and rear perspective views, respectively, of the thirdstage of manufacture of the connector of the present invention.

FIGS. 14 and 15 show rear and side views, respectively, of the fourthstage of manufacture of the connector of the present invention.

FIGS. 16 and 17 show front and rear perspective showings, respectively,of the finished connector of the present invention.

FIGS. 18 and 19 show front and side elevational showings of the finishedconnector of the present invention.

FIG. 20 shows the connector of the present invention supported in anelectrical box.

FIG. 21 shows the connector of FIG. 20 with a pull out load placedthereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides an electrical connector 10 which is usedto terminate a cable 12 to a knockout 14 in a wall 16 of an electricalenclosure 18. In the present illustrative embodiment, connector 10 isused to terminate a flexible armored cable 12 which includes a helicalgroove 12 a thereabout to enhance flexibility. The armored cable 12supports a plurality of electrical wires (not shown) therethrough fortermination within the electrical enclosure 18.

As is generally shown in FIG. 1, connector 10 includes a connector body22 having a forward end 24, an opposed open rearward end 26 and agenerally cylindrical wall 28 extending therebetween defining aconnector interior 30 for accommodating end 12 b of cable 12. Theforward end 24 of connector 10 includes a central opening 32 for passageof electrical wires (not shown) of cable 12 therethrough. An insulativethroat 33 may be applied to forward end 24 as is well known. As will bedescribed in further detail hereinbelow, the connector 10 includes aplurality of outwardly extending tabs 34 which engage the walls 16 ofenclosure 18 to secure the connector thereto. The extending tabs 34include front tabs 34 a and rear tabs 34 b which engage either siderespectively of wall 16 of enclosure 18. Connector 10 further includes aplurality of inwardly directed fingers 36 which engage the helicalgroove 12 a of cable 12 to secure the cable to the connector. Theconnector 10 is preferably formed of a suitably conductive metal so thatelectrical continuity is established between armored cable 12 and thewall 16 of enclosure 18. The inwardly extending fingers 36 and theoutwardly extending tabs 34 assist in establishing such electricalcontinuity.

The manufacture of the connector of the present invention may now bedescribed.

Referring to FIGS. 2 through 4, the first stage of manufacture is shown.Connector body 22 is formed from flat metal blank and is stamped to havethe shape shown in FIG. 2 which includes the forward end 24 defining acircular member having a plurality of radially extending side walls 29which, as will be described in further detail hereinbelow, are used toform cylindrical wall 28. Conventional stamping techniques may be usedto form the configuration shown in FIGS. 2-4.

The second stage of manufacture of the connector of the presentinvention is shown in FIGS. 5-7. Each of the side walls 29 are furtherstamped to form extending tabs 34 including front tabs 34 a and reartabs 34 b. These tabs may be punched out from the flat blank inconventional fashion.

The third stage of manufacture of the connector 10 of the presentinvention is shown in FIGS. 8-13. The side walls 29 are bent to placethem generally perpendicular to the forward end 24 so that the sidewalls 29 collectively form cylindrical wall 28. This is more fully shownin the perspective views of FIGS. 12 and 13. The side walls 29 are bothdeflected about forward end 24 and slightly curved to form the overallcylindrical configuration. This also defines the cylindrical connectorinterior 30. As constructed, in the position shown in FIGS. 12 and 13,it may be appreciated that the side walls 29 are deflectablycantilevered from the forward end 24.

The fourth stage of manufacture of connector 10 is shown with respect toFIGS. 14 and 15 where the inwardly directed fingers 36 are formed ineach side wall 29. The fingers 36 extend into the interior 30 ofconnector 10 for engagement with the armored cable 12 (FIG. 1).

The finished connector body 22 is shown in FIGS. 16-19. The body 22 isformed for use into a generally cylindrical shape. The side walls 29form the cylindrical wall 28.

Having described the manufacturer of the connector body 22 of thepresent invention, its use may be seen with respect to FIGS. 20 and 21.

It is contemplated that the connector body 22 formed in its finalconfiguration as shown in FIG. 1 and having insulated throat 33 appliedto the forward end 24 thereof may be inserted into the knockout 14 ofelectrical enclosure 18. The cylindrical wall 28 inwardly deflects toallow insertion into the knockout 14. Front tabs 34 a pass through theknockout so that the front tabs 34 a abut against the inside surface ofwall 16 while the rear tabs 34 b abut against the outside surface ofwall 16. Since the side walls 29 are deflectable in a cantileveredfashion from forward end 24, such insertion is permitted.

Thereafter, armored cable 12 may be inserted into the interior 30 ofconnector 10. Inwardly directed fingers 36 make engagement with thehelical grooves 12 a. Insertion of the cable 12 into the interior 30 ofconnector 10 serves to expand the cantilevered side walls 29 so thatsecure engagement is made between the connector 10 and the enclosure 18.This secures the connector to the enclosure and the cable to theconnector. Electrical continuity is established between the armoredcable 12 and the metallic enclosure 18 by virtue of the forwardlydirected fingers 36 and the extending tabs 34.

As may be appreciated, the connector 10 of the present invention issecurely retained to cable 12 in the knockout 14 of the electricalenclosure 18. Not only does the present invention establish electricalcontinuity between the armored cable 12 and the enclosure 18 but alsoprovides for strain relief of the cable attached to the electricalenclosure such that when a load is placed on the cable tending to pullthe cable from the enclosure 18, the connector securely retains thecable in the knockout of the electrical enclosure.

Referring now to FIG. 21, the effect of a pullout load placed on thecable 12 is shown.

It is contemplated that a load placed on cable 12 in the direction ofarrow A will cause the inwardly directed fingers 36, which are seated inthe groove 12 a of the cable 12 (FIG. 1), to inwardly deflect intotighter engagement with the cable. As the fingers 36 are seated betweenadjacent raised convolutional 12 b of cable 12, a withdrawal force inthe direction of arrow A will urge the fingers 36 further into the cable12. This in turn causes limited outward deflection of the side walls 29.Continued outward deflection of the side walls 29 is limited by thesecure positioning of the connector 10 in knockout 14 of enclosure 18.

Thus, upon continued application of the pull out force, the cable 12will be maintained in mechanical and electrical engagement with theconnector 10. The force of the load is thereby transferred from theconnector to the wall 16 of the enclosure 18 which results in the bowingof the wall.

Various changes to the foregoing described and shown structures will nowbe evident to those skilled in the art. Accordingly, the particularlydisclosed scope of the invention is set forth in the following claims.

1-12. (canceled)
 13. A method of terminating an end of a cable to aknockout in an enclosure comprising: providing a connector body having aforward end and a plurality of side walls extending from said forwardend in cantilevered fashion to form an interior cavity; inserting saidforward end of said connector body into said knockout with said sidewalls deflecting inwardly to permit said insertion; and inserting saidcable end into said cavity of said body supported in said knockout toretentively support said cable to said enclosure.
 14. A method of claim13 wherein said providing step includes providing said side walls withoutwardly extending tabs for engaging said wall of said enclosure uponsaid connector body inserting step.
 15. A method of claim 13 whereinsaid providing step includes providing inwardly extending fingers onsaid side wall for engaging said cable upon said cable inserting step.16. A method of claim 15 wherein said cable inserting step furtherincludes expanding said cantilevered side walls to provide secureengagement between said connector body and said enclosure.
 17. A methodof claim 13 wherein said connector body side includes front tabs andrear tabs outwardly extending therefrom and wherein upon said connectorbody inserting step, said front tabs pass through said knockout to abuton one surface of said enclosure and said rear tabs abut an oppositesurface of said enclosure.